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0 pointsConst-me5y ago0 comments

> Local lambdas are ideal for this.

The problem with lambdas, you can't mark their operator() with __forceinline or __attribute__((always_inline)) attributes. For this reason, when writing high-performance manually vectorized code, lambdas are borderline useless.

> MSVC is not what you should be using if you want performance.

Security and compatibility has higher priority. gcc and clang don't deliver their C runtime libraries with windows updates. Also, debugging and crash diagnostic is much easier with MSVC.

It's same on Linux BTW, only with gcc.

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jfkebwjsbx5y ago

> when writing high-performance manually vectorized code

The point was not about manually vectorized loops in particular. Why is that a problem if you are manually doing it, though?

> Security and compatibility has higher priority.

In commercial games, not really.

As for "compatibility", I am not sure what you mean.

> gcc and clang don't deliver their C runtime libraries with windows updates.

AFAIK you can use Windows libraries just fine. No need for using a different libc.

> Also, debugging and crash diagnostic is much easier with MSVC.

AFAIK, Clang can produce debugging info that you can use with VS.

I don't work on the environment, but it is what I have read here.

Const-meOP5y ago

> Why is that a problem if you are manually doing it, though?

Here’s couple examples: https://github.com/Const-me/DtsDecoder/blob/master/Utils/App... https://github.com/Const-me/SimdIntroArticle/blob/master/Flo... I would like to use lambdas instead of classes, but can’t, due to that defect of C++.

> In commercial games, not really.

In commercial games too. While they don’t care about security, they do care about compatibility and crash report diagnostics.

> As for "compatibility", I am not sure what you mean.

A windows update shouldn’t break stuff. A software or a game should run on a Windows released at least 10 years in the future.

> Clang can produce debugging info that you can use with VS.

According to marketing announcements. This page however https://clang.llvm.org/docs/MSVCCompatibility.html only says “mostly complete” and also “Work to teach lld about CodeView and PDBs is ongoing”. PDB support is not about VC compatibility, it’s about Windows compatibility really: the debugger engine is a component of OS, even of the OS kernel. WinDbg is merely a GUI client for that engine, visual studio is another one.

Overall, in my experience, the platform-default compilers cause the least amount of issues. On Windows this means msvc, on Linux gcc, on OSX clang. Technically gcc and clang are very portable. Practically, when you’re using a non-default toolset, you’re a minority of users of that toolset, e.g. the bugs you’ll find will be de-prioritized.

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